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Biomedical subjects

N Ishida

Publications and source records attributed to N Ishida.

At least 289 records · Page 16Linked to original sources
PubMed1988

Preparation of a monoclonal antibody specific for 1-methyladenosine and its application for the detection of elevated levels of 1-methyladenosine in urines from cancer patients.

A monoclonal antibody specific for a modified nucleoside, 1-methyladenosine, was prepared and characterized. This antibody, termed AMA-2, reacts with 1-methyladenosine and 1-methyladenine but not with other nucleosides, particularly methylated adenosines other than 1-methyladenosine and methylated guanosines, tested in this investigation. In our experiments, AMA-2 was used in an enzyme-linked immunosorbent assay (ELISA) system for the quantitation of the levels of 1-methyladenosine in urine. Sensitivity was in the picomole range and accuracy was nearly equal to that of the high-performance liquid chromatography (HPLC) assay system. Urinary levels of 1-methyladenosine in healthy donors and patients with various advanced cancers were determined by the inhibition ELISA. The amount of 1-methyladenosine in urine of 33 healthy donors was 1.91 +/- 0.66 nmol/mumol creatinine. In 54% (51/94) of patients, urinary 1-methyladenosine was elevated above the mean plus 2 standard deviations for the healthy donors (3.23 nmol/mumol creatinine). In patients with leukemia, esophageal cancer, stomach cancer, colon cancer, and bladder cancer, urinary levels of 1-methyladenosine were significantly elevated. In patients with leukemia, urinary 1-methyladenosine levels changed almost in parallel with the change in the clinical response during chemotherapy. These results suggest that urinary 1-methyladenosine might be useful in monitoring the effectiveness of therapy.

Adenosine↗
PubMed1988

An antitumor polypeptide antibiotic neocarzinostatin: the mode of apo-protein--chromophore interaction.

The mode of neocarzinostatin-chromophore (NCS-chr)-apo-neocarzinostatin (apo-NCS) interaction in neocarzinostatin (NCS) complex has been described. The NCS-chr release from the NCS complex in the presence of various reagents, which destroy the high-order structure of the protein under various pH conditions, was examined. We found that (i) sodium dodecylsulfate, Nonidet P 40, 8 M urea, and 2-propanol did release NCS-chr from NCS, (ii) no NCS-chr release is detected below pH 7, but it is enhanced at high pH and (iii) beta-naphthol as a model of naphthalenecarboxylic acid derivative and D-galactosamine as a model of N-methylfucosamine of NCS-chr did release NCS-chr from NCS. These observations indicate that the binding of NCS-chr to apo-NCS may be due to not only ionic interaction between the acidic side chain of apo-NCS and the basic center of an aminosugar moiety of NCS-chr but also hydrophobic interaction between the hydrophobic amino acids of apo-NCS and hydrophobic moieties of NCS-chr. Apo-NCS is a very hydrophilic protein, since it has an high hydrophilic amino acid content. So, local hydrophobicity, local hydrophilicity and secondary structure of apo-NCS were predicted. Hydrophobic residues of apo-NCS predominantly located in beta-sheet structures near the carboxyl-terminus. These predictions are in good agreement with the results suggesting that NCS-chr bound carboxyl-terminal-43-peptide of apo-NCS in our previous result.

Amino Acid Sequence↗
PubMed1987

The human IL-2 receptor gene contains a positive regulatory element that functions in cultured cells and cell-free extracts.

The 130-base pair fragment located between 220 and 90 base pairs upstream of the major transcription initiation site of the human interleukin 2 (IL-2) receptor gene had positive regulatory effect on the early promoter of simian virus 40 as well as its own promoter. This fragment seems to be responsible for not only cell-specific but also lymphokine-induced expression of the IL-2 receptor gene as assessed by DNA transfection. The same DNA fragment directed cell-specific transcription of the IL-2 receptor gene in extract of HTLV-I-infected T cells, MT-1, but not of Epstein-Barr virus-transformed B cells, CESS. The addition of small amounts of MT-1 extract to CESS extract resulted in specific expression of the IL-2 receptor gene, indicating that cell-specific expression is regulated by trans-acting molecules in MT-1 extract.

Animals↗
PubMed1987

Serologic characteristics of a human rotavirus isolate, AU-1, which has a "long" RNA pattern and subgroup I specificity.

An unusual human rotavirus (HRV) isolate, designated AU-1, has a "long" RNA electrophoretic pattern and subgroup I specificity, in contrast to properties common to HRVs previously isolated. Hemagglutination activity of the AU-1 strain was demonstrated using erythrocytes of 1-day-old chicken. Neutralization assays revealed that the AU-1 strain was crossneutralized by hyperimmune antisera against the MO strain (serotype 3). However, antiserum directed against a reassortant in which the gene for Vp7 was replaced by the corresponding AU-1 gene neutralized the AU-1 strain to a significantly higher titer than the MO strain.

Hemagglutination Tests↗
PubMed1987

Effect of trypsin and chymotrypsin on polypeptides of human rotavirus KUN strain.

In view of the fact that trypsin enhances the infectivity of human rotavirus and decreases its hemagglutination, the trypsin-mediated structural modification of the viral polypeptides was analysed, using the KUN strain, a cultivable human rotavirus isolate, grown in the absence of trypsin. A major polypeptide sensitive to trypsin treatment was Vp4 with a molecular weight of 80,000, being cleaved into three polypeptides with molecular weights of 54,000 (P54), 30,000 (P30), and 24,000 (P24). Vp4 was also sensitive to chymotrypsin treatment, generating cleavage products different from those obtained with trypsin.

Animals↗
PubMed1987

Evidence for endocytosis-independent infection by human rotavirus.

The effects of five lysosomotropic drugs (NH4Cl, chloroquine, methylamine, amantadine and dansylcadaverine) and cytochalasin B on human rotavirus (HRV KUN strain) and vesicular stomatitis virus (VSV Indiana strain) infection in monkey MA 104 cells were examined. These drugs had little effect on HRV yield but greatly reduced VSV yield. The results strongly suggest that HRV does not require endocytotic activity and intracellular acidic vesicles for the initial stage of infection and support our postulate that HRV enters the target cell by direct penetration of its nucleoid through the cell membrane.

Amantadine↗
PubMed1987

Nucleotide sequence of the hemagglutinin-neuraminidase gene of Newcastle disease virus avirulent strain D26: evidence for a longer coding region with a carboxyl terminal extension as compared to virulent strains.

The nucleotide sequence of DNA clones complementary to the genomic RNA of an extremely avirulent strain D26 of Newcastle disease virus was analyzed, and the sequence of 2102 nucleotides directly following F gene reported previously (Sato et al., 1987, Virus Res. 7, 241-255), and corresponding to HN0 gene was determined. A long open reading frame coding for the HN0 peptide of 616 amino acid residues was found in this sequence. It was flanked by the consensus sequences N1 and N2 (Ishida et al., 1986, Nucleic Acids Res. 14, 6551-6564), and the former was shown by the primer extension method to serve as the transcriptional initiation site. The deduced amino acid sequence of the HN0 peptide was highly homologous to that of the HN peptides of strains Beaudette C and B1, but had a carboxyl terminal extension of 39 amino acid residues with a potential glycosylation site in it. The terminal extension is likely to be excised during the processing, and this is consistent with the observation that unglycosylated HN0 is larger in size than unglycosylated HN. A microheterogeneity among the cDNA clones in the nucleotide sequence was also noted which may be relevant to the synthesis of a small amount of an HN-sized peptide in strain D26-infected cells.

Amino Acid Sequence↗
PubMed1987

Molecular cloning and nucleotide sequence of P, M and F genes of Newcastle disease virus avirulent strain D26.

Molecular cloning of most if not all of the genome of an avirulent strain D26 of Newcastle disease virus (NDV) was carried out. cDNA clones were aligned by mutual hybridization and restriction map analysis. The nucleotide sequence of 3672 bases which completed the partial sequence of P gene reported in our previous paper (Ishida, N. et al., 1986, Nucleic Acids Res. 14, 6551-6564), and also covered M and F genes, was determined. Each gene contained one long open reading frame which could code for polypeptides of 395, 364, and 553 amino acid residues, respectively. The deduced amino acid sequences of P and M gene products showed little homology to those of other paramyxoviruses. In contrast, comparison of the amino acid sequence of the F gene product revealed highly conserved regions including the amino terminal sequence of the F1 portion following the putative processing site. There was only one basic amino acid residue at the putative processing site, which would explain the low virulence of this strain.

Base Sequence↗
PubMed1987

Synthesis and beta-lactamase inhibitory properties of 2 beta-[(1,2,3-triazol-1-yl)methyl]-2 alpha-methylpenam-3 alpha-carboxylic acid 1,1-dioxide and related triazolyl derivatives.

Benzhydryl 2 beta-[(1,2,3-triazol-1-yl)methyl]-2 alpha-methylpenam- 3 alpha-carboxylate 1,1-dioxide was prepared by heating benzhydryl 2 beta-(azidomethyl)-2 alpha-methylpenam-3 alpha-carboxylate 1,1-dioxide with (trimethylsilyl)acetylene. The ester group was removed by hydrogenolysis to give sodium 2 beta-[(1,2,3-triazol-1-yl)methyl]-2 alpha-methylpenam-3 alpha-carboxylate 1,1-dioxide (3i, YTR-830), which was found to be a potent inhibitor of various bacterial beta-lactamases. A series of related compounds was prepared in a similar way, and all of these compounds show excellent beta-lactamase inhibitory properties.

Ampicillin↗
PubMed1987

Interferon-alpha A/D blocks an increase in Fc receptors of a human promyelocytic leukemia cell line (HL-60) induced by other recombinant interferons.

The effect of recombinant hybrid interferon (IFN)-alpha A/D either alone or in combination with retinoic acid (RA) on induction of differentiation of the human promyelocytic leukemia cell line HL-60 was studied. The combination of 10 nM RA and IFN-alpha A/D at concentrations of 120 units/ml and higher induces differentiation into cells having many monocytic characteristics such as monocyte-like morphology, ability of superoxide anion production, antibody-dependent cellular cytotoxicity, and nonspecific esterase activity. However, this combination does not induce an increase in IgG Fc receptors (Fc gamma R) and immunoerythrophagocytosis. IFN-alpha A/D alone shows essentially no effect on these parameters. Pretreatment of HL-60 with IFN-alpha A/D blocks the Fc gamma R-increasing activity of IFN-alpha A, IFN-alpha D, and IFN-gamma. This block is complete after a 2-h pretreatment for IFN-alpha A and IFN-alpha D and after a 6-h pretreatment for IFN-gamma. Furthermore, an increase in Fc gamma R-mediated phagocytosis is also suppressed by the pretreatment. However, IFN-alpha A/D does not suppress superoxide anion production. These results indicate that the block of an Fc gamma R-increase by IFN-alpha A/D has not resulted in the competitive inhibition at IFN receptors, but may occur in intracellular events such as postreceptor transduction for the expression of Fc gamma R.

Cell Differentiation↗
PubMed1987

A microplate method for isolation of viruses from infants and children with acute respiratory infections.

Between December 1984 and December 1986, a microplate technique was adopted for isolation of viruses from infants and children with acute respiratory infections. By using two kinds of tissue culture microplates, i.e., the HHVM plate, containing human embryonic fibroblast (HEF), HEp-2, Vero and MDCK cells, and the MK plate which contains secondary monkey kidney cells, 1,080 field viruses were isolated from 1,061 (24.9%) out of 4,254 throat swabs. Of these 1,080 isolates, 1,003 (92.9%) were recovered in the HHVM plates and the remaining 77 (7.1%) in the MK plates. With the HHVM plate, influenza A and B viruses were cultivated in MDCK, RS virus in HEp-2, parainfluenza and mumps viruses in Vero, adenoviruses in both HEF and HEp-2, polioviruses in HEF, HEp-2 and Vero, coxsackie B viruses in both HEp-2 and Vero, rhino and echo viruses in HEF, herpes simplex virus in both HEF and HEp-2, and cytomegalovirus in HEF, although MK were more sensitive than Vero to parainfluenza and coxsackie B viruses. There was no difference in the rate of isolation of viruses between the microplate and ordinary tube methods. Cross contamination in the microplates was negligible for routine work.

Acute Disease↗